Sand-blast machine.



PATENTED MAY 24, 1904'.

F. P. BOLAND. SAND BLAST MACHINE. APPLICATION FILED PER. 26, 1904.

N0 MODEL.

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UNITED i 1.81 fA'rEs Patented May 24, 1904.

PATENT OFFICE. Q

FRANK-P. 'BOLAND, ofirnovmnncn, RHODE ISLAND.

' AND-BL T"MACHINE.

-' SPECIFICATION forming part or Letters Patent No. 7 6O,775, dated ma a4, 1904. v

I V I Application filed February 26, 1904;. V SerialNo. 195,364. (No model.) I

Toall whom it may concern:

' Be it known that I, FRANK P. BoLAun, a citizen of the United States of America, and a resident of Providence, in the county of Providence and State ofRhode Island, have invented certain new and useful Improvements in Sand- Blast Machines, of which the following is a.

specification. F p

My invention relates to sand-blast machines; and it consists, essentially, in the improved construction and arrangement of means for conducting and controlling the flow of the air and sand or abrading material to and from the operating-chamber, all as will be more fully hereinafter set forth and claimed.

In the accompanying sheet of drawings,Fig ure 1 is a front side elevation of a sand-blast machine embodying my improvement; and Fig. 2 is a partial front view, in reduced scale, showing a modification.

In the organized sand-blast machine or apparatus A (represented in the drawingslthe operating-chamber a, inclosed within a suitable frame having glass or transparent sides, the hinged front 6/, provided with hand-holes h h. beveled top (0 hopper-shaped bottomb, andsupporting-legs Z are oivmay be made substantially as common or usual.

At the center and lowerend of the bottom I) is an outlet-pipe (Z and valve d, through which the used or spent sand flows by gravity into the larger circulating-piped, communicating with the upper part of the machine. The sand is forced along and upwardly in said pipe 0Z by air under suitable pressure flowing through pipe 0, via valve 0 and reduced airdischarge nozzle 0 the latter being mounted in pipe d and forming an ejector or induced current in a well-known manner.

To the center or apex of the top casing member a is secured a hollow fitting 0, communicating with said air-pipe c by means of the branch pipe 0 and interposed valve 0 The lower portion of member 6 extends'downwardly into the operating-chamber a and forms the nozzle 6, from which the sand is discharged by the combinedaction of gravity and the force of the air flowing into the noz-' zle via pipe 0 &c.

The sand just referred to is conducted into thenozzle e by means of the circulating-pipe I (V, valve J and reduced pipe d the-latter exouter air a large vent-pipe or' exhaust-pipe f is employed, the same being in direct open communication therewith through the top of the casing. An open branch pipe d unites the pipes f and d thereby practically relieving the latter from any plus or back pressure at that point and permitting the sand to flow into the nozzle-pipe d by gravity.

By means of my improved manner of constructing and arranging the. connections it will be obvious that a'continuous flow of the sand or abrading material may be attained at thedischarge end of the nozzle e,'the volume and pressure of the outflowing sand being readily'controlled as desired by means of the several valves or cocks.

The spent sand flowing into the lower end of pipe 03 is taken up by the air-blast and carried past the upper bends in the pipe, after which the airpressure is automatically relieved by escaping via the open piped into exhaust-pipef, the sand then flowing by gravity alone into the nozzle 0. Except that at times it is desirable to control the quantity of sand discharged from said nozzle the valves 03 and d may be omitted, the force or impact of the sand being practically controlled by the air-valves 0 '0 I In lieu of the arrangement of the exhaust A or relief piping, as shown in Fig. 1, the circulating-pipe 03 may be provided'with' branch is more uniform.

' eration in which the used sand or abrading material is carried under pressure to the top of the machine and discharged from a nozzle located in the operating-chamber.

I claim as my invention and desire to secure by United States Letters Patent 1. In a sand-blast machine provided with a main operating-chamber, the combination of a sand carrying or circulating pipe 65 communicating with the lower end of said chamber, an air-blast pipe connected with said pipe 03 a stationary hollow top fitting e, having an open discharge-nozzlee extending downwardly into said chamber in communication with the outlet ends of said circulating and air pipes, an inner discharge-pipe 03 secured to or forming a continuation of said pipe d extending downwardly through fitting 6 and into the nozzle 0', and an exhaust-pipe in open communication both with the chamber and with the circulating-pipe, whereby the pressure upon the flowing sand in the latter pipe is relieved before it escapes from the discharge-pipe cl, substantially as described.

2. In a sand-blast machine or apparatus, the combination with the operating-chamber a provided at the top with a hollow fitting 0 extending downwardly into the chamber, and means for transferring or conducting the waste or used sand from the bottom of the chamber to the top thereof, of a valved airblast inlet communicating with said member 0, a valved connection located in the sand-conducting device having a discharge-pipe leading downwardly therefrom through litti ng e, and a continuously open exhaust-duct lead ing from said chamber and sand-conducting means, whereby the sand is adapted to drop into the discharge-pipe d by gravity, substantially as shown and described.

Signed at Providence, Rhode Island, this 24th dayof February, 1904.

FRANK P. BOLAND.

Witnesses:

GEO. H. REMINGTON, WILLIAM A. SULLIVAN. 

